Data/hora: 05/06/2024 18:23:38

Biblioteca(s): | Embrapa Meio Ambiente.
Data corrente: | 20/12/2013
Data da última atualização: | 07/03/2014
Autoria: | ROSA, L. H.; QUEIROZ, S. C. do N. de; MORAES, R. M.; WANG, X.; TECHEN, N.; PAN, Z.; CANTRELL, C. L.; WEDGE, D. E.
Afiliação: | LUIZ H. ROSA, ICB-UFMG; SONIA CLAUDIA DO N DE QUEIROZ, CNPMA; RITA M. MORAES, University of Mississippi; XIAONING WANG, University of Mississippi; NATASCHA TECHEN, University of Mississippi; ZHIQIANG PAN, USDA-ARS; CHARLES L. CANTRELL, USDA-ARS; DAVID E. WEDGE, USDA-ARS.
Título: | Coniochaeta ligniaria: antifungal activity of the cryptic endophytic fungus associated with autotrophic tissue cultures of the medicinal plant Smallanthus sonchifolius (Asteraceae).
Ano de publicação: | 2013
Fonte/Imprenta: | Symbiosis, Philadelphia, v. 60, p. 133-142, 2013.
Idioma: | Inglês
Conteúdo: | Few studies have addressed the presence and bioactivity of endophytic fungi living in plantlets growing under in vitro conditions. After unfruitful attempts to grow axenic shoot cultures of the medicinal plant Smallanthus sonchifolius (yacon) were made, healthy shoots grew on half strength Murashigue and Skoog media supplemented with 2.2 mM benzylaminopurine without sucrose. We isolated a fungusUM109 from these autotrophic tissue cultures and it was identifiedas Coniochaeta ligniaria using molecular, physiological and morphological methods. Dichloromethane extracts from C. ligniaria and its host S. sonchifolius exhibited antifungal activity against phytopathogenic fungi Colletotrichum acutatum, C. fragariae and C. gloeosporioides. Both extracts of C. ligniariaand S. sonchifolius were subjected to antifungal bioassaydirected fractionation using NMR spectroscopy and GC-FID analysis. Twelve antifungal fatty acids were identified and 8 out of the total were produced by the fungus and the plant including caproic, caprylic, myristic, palmitic, heptadecanoic, stearic, oleic and linoleic acids. Additionally, caproic, caprylic and palmitic acids were produced at high concentrations by the endophytic fungus and its host. The detection of these antifungal fatty acids produced by both C. ligniaria and S. Sonchifolius suggests that these bioactive compounds may be partially responsible for the high resistance of S. sonchifolius to phytopathogenic fungal attacks. This finding also indicates the existence of an interesting chemical symbiosis between an endophytic fungus and its host. Furthermore, the isolation of C. ligniaria from tissue culture of S. sonchifolius demonstrates that plantlets growing in vitro as autotrophic cultures can shelter specific endophytic fungal communities. The use of autotrophic tissue cultures may become an important tool for studies on the taxonomy, ecology, evolution and biotechnological application of endophytes.
Palavras-Chave: | Propriedades antifúngicas; Yacon.
Thesagro: | Ácido graxo; Fungo; Planta medicinal.
Thesaurus Nal: | Antifungal properties; Coniochaeta ligniaria; Fatty acids; Medicinal plants; Smallanthus sonchifolius; Symbiosis; Tissue culture.
Categoria do assunto: | --
Registro original: | Embrapa Meio Ambiente (CNPMA)
Exemplares: | CNPMA - (12861-1) - UPC - AP - DD -  -  -  - DIS